RC5 fixes an issue with the type juggling for theme settings introduced in RC4 where the font settings caused a fatal error due to bad return value of the setting (which in turn caused a file not be included and thus the fatal error for an undefined function).
This juggling has been removed and instead I have changed some comparison operators where they were known to cause issues on some systems, namely in theme_breadcrumb.
Issue #1518172 by iamEAP: Undefined index in field migration.
Removal of patch file.
Issue #1593646 by danielb: Handle themes.
Added deprecated notice to Select list with drag and drop sort.